<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>03_边框与内间距</title>
    <style>
        .d1{
          width: 200px;
          height: 200px;
          background-color: #0aa1ed;
          border: 5px solid #f00;
          border-top:5px dotted #ff0;
          border-radius: 30px;
        }
        .d2{
          width: 200px;
          height: 60px;
          background-color: cyan;
          border-radius: 30px;
        }
        .d3{
          width: 200px;
          height: 100px;
          background-color: purple;
          border-radius: 100px/50px;
        }
        .d4{
            width: 200px;
            height: 200px;
            background-color: lightsalmon;
            border: 10px solid #000;
            padding-left: 50px;
            margin: 50px;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
    <div class="d1"></div>
    <div class="d2"></div>
    <div class="d3"></div>
    <div class="d4"></div>
</body>
</html>